The Art School: ‘I’ve a soft spot for the old-timers, but this isn’t classic, it’s dated.’ Photograph: Rebecca Lupton for the Guardian

Everybody I speak to in the business tells me that Paul Askew is the loveliest of men, a chef garlanded with plaudits and the acclaim of his peers. And I love Liverpool, so I’m delighted that his new restaurant has been met with gibbering approbation from local diners. But after dinner here, instead of rushing off to spread the word, all I want to do is apologise.

The Art School, Askew’s first independent restaurant (he was formerly chef of The London Carriage Works around the corner), was making all the right “reaching for the stars” noises. The timing, with the reopening of the Philharmonic Hall, couldn’t be more perfect, and it doesn’t take a genius to figure out what the subtext is, what with its bowler-hatted doorman, splashy scarlet upholstery, modern art and metres of starched linen, in this former Victorian home for destitute children. (Shades of Oliver!, although, alas, I won’t be asking for more.)

A glass of champagne arrives with the canapés, setting out the stall as determinedly as an Apprentice contestant. There are two menus: Excellence, at £65 for five courses (I’m not sure I count canapés, including olives and a bendy croute of treacle-cured salmon, or “amuse bouche decided by the chef” as actual courses), and Tasting Menu – a few dishes more for an enthusiastic £85. According to the website, there’s also a £45 Market Menu, but we aren’t offered it.

Anyway, biting the bullet: I just don’t think the food is very good. I’m examining my conscience, like the good Catholic girl I am. Perhaps it’s simply not to my taste? But there are too many elements that are fundamentally wrong: limp, floppy skin on a “Northop red-leg partridge” breast. Its little leg doesn’t taste confited, but old and chewy and tired, like Christmas dinner eaten on the Epiphany. An exciting-sounding “Cox apple tatin” is a tiny dome of apple on a flabby disc of pastry. The caramel sauce squeezy-bottled cursively under one of our puddings is gritty with unmelted sugar. Deliberate? Surely not. Puy lentils heaped over a fine chunk of Chelford Black pork are undercooked – not al dente, more actual bullet-biting.

And it’s all so old-fashioned. I’ve a well-documented soft spot for the old-timers, but this isn’t classic, it’s dated. The odd nods towards a modern culinary canon are clunky: a mushroom broth poured over our amuse of good pickled squid issues from a teapot that’s more Brown Betty than delicate vessel; a frisee and apple salad that modishly clings to the plate rim of a starter of scallops, with smoked pork loin and too many sickly sweet golden sultanas, looks like an afterthought.

Some items come on slates, but this looks positively cutting edge beside the kitchen’s fondness for huge, square, textured glass plates – last seen when Antony Worrall Thompson roamed the Earth. Dishes are cluttered with little hummocks of this, roulades of that: a “Claremont Farm potato gateau” with the partridge, plus a wildly oversalted parcel of cabbage and some cloying parsnip puree. That gritty, slate-plated dessert is titled “Theme on caramel” – oh, cringe – and features a slice of dry sponge and another clumsy tatin.

It’s the kind of old-school dining experience that some people mistakenly see as bang for buck. There’s no sense that anyone involved has eaten in an ambitious restaurant outside Liverpool since the turn of the century.

So what’s good? Oh, lord, I’m struggling here. There’s some glorious baking: tall, pillowy focaccia studded with fennel seeds, every bit as fine as April Bloomfield’s legendary version; a shade less syrupy and that scallop starter would be fabulous. And the staff are wonderful: cheery, chatty girls, clued-up Spanish sommelier, and delightful restaurant manager James Campbell, last seen at Fraiche on the Wirral (voted by the Harden’s Guide as the UK’s best restaurant. Hmm). Sadly, he appears to have brought his white glove habit with him.

So here are my apologies: I apologise to Askew for having to be so critical when he’s clearly putting in heart and soul – his broad back is visible in the open kitchen at all times, radiating intensity of purpose. I apologise to Liverpool: I’m not sure this is the game-changer the pre-publicity suggests you’ve been waiting for. And most of all I apologise to the pal who had to plough through those lentils.